The major objective of this study is to conduct a comprehensive study of the pharmacokinetics (kinetics of absorption, distribution, metabolism, elimination and accumulation) and chronic toxicity of several commonly used fluorocarbon aerosol propellants such as propellants 11, 12, 113 and 114 in animals and to correlate their pharmacokinetic and biophysical parameters with some of their possible chronic and acute adverse effects in humans and animals. Initially, a highly sensitive assay method for the propellants will be developed using a modified head-space and gas chromatographic method. A unique intravenous administration of these propellants to dogs will be developed in order to obtain accurate pharmacokinetic parameters such as volume of distribution, and biological half-life. Based on these parameters, the absorption rate, extent and variation of absorption after each puff of inhalation from aerosols can be determined. By varying the dose administered, one can determine whether the propellant disposition follows dose-dependent kinetics. Plasma protein binding characteristics in various animal species and partition coefficients between air and blood, blood and various tissues will be investigated. Rabbits will be chronically exposed to propellant vapors at concentrations higher than present in beauty shops. Propellants and metabolites in blood and urine will be analyzed. Effects of chronic exposure on hepatic enzyme induction and inhibition (using antipyrine and warfarin as test compounds), hepatic (SGPT test) and renal (creatinine test) function, and hormone synthesis and elimination (measuring urinary excretion of 17-ketosteroids and 17- hydroxycorticosteroids) will be investigated.